The prevalence of childhood overweight (CO) has tripled in recent decades, and related health care costs have quadrupled. While lifestyle interventions for CO have produced promising short-term results, a substantial percentage of children regain all or most of the relative weight they had lost. Indeed, results from our recent NICHD-funded randomized controlled trial (RCT) of CO maintenance interventions revealed that the benefits of treatment for all three groups (Behavioral Skills Maintenance-BSM;Social Facilitation Maintenance-SFM;and No Maintenance Treatment Control-NTC) began to attenuate once treatment contact was discontinued. However, SFM treatment proved superior to NTC in inducing long-term weight maintenance and demonstrated treatment-specific effects for psychosocial targets. Building on this positive finding, our proposed study will test the efficacy of SFM+ a version of SFM that is enhanced in both content and duration. Informed by learning theory and weight maintenance research, SFM + extends the duration of treatment from 4 months to 12 months to target a broad range of social environmental contexts across time with the objective of decreasing relapse. SFM+ also includes a focus on self-regulatory skills associated with successful weight maintenance. We propose to conduct a multi-site RCT with overweight children (N=240) and their parents to evaluate the effects of two doses of SFM + on weight loss maintenance at 12-month (post-treatment) and 18-month (6 months post-treatment) follow-up compared to a credible health education (CONTROL) condition. Participants will be randomized to one of three, 12-month treatment conditions: (1) low dose SFM+[LOW;26 sessions], (2) high dose SFM+ [HIGH;52 sessions], or (3) CONTROL [26 sessions]. The CONTROL condition matches the schedule, duration, and attention of the LOW condition, but differs in treatment content. The LOW and HIGH conditions are matched on content and duration, but differ in treatment dose. We will recruit a large, diverse sample from two different metropolitan areas and deliver high quality, innovative treatments in a standardized manner. We hypothesize that the HIGH condition will produce better weight maintenance and greater improvements in associated outcomes at 12 months and 18 months than either the LOW or the CONTROL conditions, and that the LOW condition will produce better weight maintenance than the CONTROL condition. This study is the first RCT to evaluate the core questions of content and dose for weight maintenance in children. By examining mediators and moderators, our study will also provide insight regarding how maintenance treatment works and for whom it is most effective. Identifying efficacious weight maintenance strategies will positively affect the health and well being of children, and inform public health approaches to the long-term management of CO.